1. Field of the Invention
The present invention relates to a surgical microscope for use in, e.g., a surgical operation.
2. Description of the Related Art
A surgical microscope has a stand which movably supports a microscope portion having an observation mechanism. A stand of a surgical microscope disclosed in, e.g., Jpn. Pat. Appln. KOKAI Publication No. 1982-86806 has a parallelogram link mechanism which is used to move a microscope portion in a vertical direction. A spring which redresses the balance of the parallelogram link mechanism is arranged in this parallelogram link mechanism.
Further, a stand of a surgical microscope disclosed in Jpn. Pat. Appln. KOKAI Publication No. 1996-140932 has a link mechanism which moves a microscope portion in a horizontal direction and a vertical movement arm which moves the microscope portion in a vertical direction. That is, one end portion of the link mechanism is pivoted at a base bottom portion or the like, and the other end portion of the same can revolve around one end portion. The vertical movement arm is arranged at the other end portion of the link mechanism. This vertical movement arm is formed of a parallelogram link mechanism, and a spring which redresses the balance of the parallelogram link mechanism is arranged in this parallelogram link mechanism. Furthermore, the microscope portion is provided to the vertical movement arm.
Moreover, Jpn. Pat. Appln. KOKAI publication No. 1988-36481 discloses a mechanism which inclines a binocular tube of a microscope portion. An inclination arm is connected with a support portion which supports the microscope portion in such a manner that this arm can revolve around an axis extending in a horizontal direction. This inclination arm rotatably supports the binocular tube around a central axis of the binocular tube. That is, the binocular tube is moved to incline by rotation around the axis extending in the horizontal direction and rotation around the central axis of the binocular tube. Moreover, a rotation moment generated by the inclining movement of the binocular tube is canceled out by a function of a counterweight.